Quite a few $$$ involved to kit the boat out but those are good boats and it will serve well for trolling on Erie.

Here are a few suggestions:-

1. Get the 9.9 kicker mounted.

2. You may have Rod Holders but ideally you would need 4 angle adjustable ones on each side to cater for 4 people.

3. Rods - Shimano Talora 8' or 8'6" are very good but cost around $80 each.

4. Line Counter Reels and Line - Shimano Takota are great but run more than $150 each, but Okama Magda are serviceable at just under $50 each - Then you need to spool them with braid or mono.

5. Planer Boards - Inline Planer Boards by Offshore run about $30 each and more for the better line clips.

6. Stuff to get your bait down to the fish such as 2 & 3oz inline weights, maybe a few #40 Tru-Trips and there is all manner of stuff out there. Don't forget a couple of #1 Dipsy's which also are easy to use and often do well.

7. Leaders - If you pull worm harness's or some of the crank types then you will need to make up some Leaders about 6ft long.

8. Selection of crank baits, such as 800 series ReefRunners, Deep Diver Bandits and maybe a few Husky Jerks and the latest fad - Flicker Minnows.

9. Spoons do well - So add a few Stinger spoons to the arsenal.

10. Worm Harness's - Tie your own or buy them, the goto color on Erie has some purple on it somewhere.

Now the expensive stuff ....

You need to go in more or less a straight line when setting lines, trolling and when netting fish!
So an AutoPilot of some sort is so very useful especially when trolling by yourself, lots out there.

3 people fishing = 6 rods [3 per side] and you will be fine using inline planer boards once you learn how to set and retrieve them without big tangles.
4 people fishing = 8 rods [4 per side] puts you in the next bracket, trolling with Big Boards, and all the additional gear needed to use them.

And make sure you have a good modern Sonar Fish Finder .........

Now if you would like a shopping partner, I could really enjoy buying all the above ... lol
But, before you start buying get out on the lake with someone who trolls and see what gear they are using and how they use it.

Have fun and hope the above helps to start the thinking!